The taking or deprivation of life
Killing is defined as the taking or depriving of life. In modern English, it does not necessarily imply murder: manslaughter and self-defense being two examples of killing that are not murder.
Exodus 20:13 is rendered "Thou shalt not kill" in the older King James version of the Bible. Modern translations, such as the ESV, read "You shall not murder." The ESV footnote on the verse says:
The Hebrew word also covers causing human death through carelessness or negligence.
